Very interesting question!
I think that the resistors were added to lower the overall figure of merit (Q) and for better impedance matching throughout the bandwidth of the antenna.
Something similar is used in the stripline and Vivaldi microwaves antennas.
At lower frequencies the use of resistors and inductors suitably positioned in the open dipoles antennas is at the basis of many experimental antennas used by radio amateurs.
The circuit may be fed
to some EM simulator but should at least know the exact dimensions of the strips and, at least in my case, should have a few years younger and a few neuron more...